Reason

62. The distinction made by thought

We sometimes distinguish a substance from one of its attributes.

• Without those attributes, it would be impossible for us to understand that substance

We attempt to separate 2 such attributes of a substance by thinking of one without thinking of the other.

We cannot have a clear and distinct idea of such a substance if we remove a particular attribute

We cannot conceive one of two or more attributes clearly if we separate it from the others.

For example, no substance can continue to exist once it stops enduring.

Time [duration] is distinct from substance only by thought.

The attributes of a body can lead to diverse thoughts about that body.

Examples of such attributes are:

• the length, width, height of a body
• the divisibility of a body

These attributes differ from the body itself and from each other.

• This is only because we sometimes think confusedly about one without considering the other.

My Meditations on First Philosophy received objections.

• So I clarified it by mixing the distinction made by thought with the modal distinction.
• But this is not contrary to what I write here because back then, I did not intend to treat the subject at great length.
• So back then, I merely distinguished both kinds from the real distinction.

63. Thought [aether] is the nature of mind, extension [aetherspace] is the nature of body

• Thought [aether] is the principal attribute of intelligent substances, as souls.
• Extension [aetherspace] is the principal attribute of physical substances, as bodies.

It is easier to know a thinking substance or an extended substance than to know a substance by itself without its attributes of thought or length, width, height.

This is because substance is a very abstract concept, more abstract than thought and length, width, height.

This is beause we sometimes consider thought or length, width, height without reflecting on the thing that has those attributes.

Our conception of substance is abstract not because it has less details, but because it is hard to identify it without its attributes.

64. How the attributes of thought [aether] and extension [aetherspace] may be distinctly conceived as modes of substance.

A soul can have many different thoughts.

A single body, while maintaining the same size, can be extended in various ways—sometimes more in length and less in width or depth, and sometimes vice versa.

We distinguish thought from the soul, and extension from the body only as dependent features of that soul or body.

We then understand them as clearly and distinctly as we do their corresponding substances.

• This is provided we do not suppose that they exist independently, but only as dependencies of those substances.

When we consider them as properties of their substances, we can easily:

• distinguish them from those substances and
• treat them as what they truly are.

Whereas, if we considered them apart from substance, we might think that they exist by themselves.

• We would then confuse our idea of substance with the idea of its properties.

65. How we also conceive the properties or attributes of the modes of thinking and body.

The different modes of thinking are understanding, imagining, remembering, willing, etc.

The various modes of extension are shapes, the arrangement of parts, and their movements.

We can conceive these provided we consider them as dependencies of their substances.

As for movement, we can regard it as another mode dependent on substance that has length, width, height. as long as we think only of the motion that occurs from one place to another without investigating the force that produces it.